"Only Google is allowed to scrape the web."

If I'm not mistaken, the plaintiffs in the US v Google antitrust litigation in the DC Circuit tried to argue that website operators are biased toward allowing Google to crawl and against allowing other search engines to do the same

The Court rejected this argument because the plaintiffs did not present any evidence to support it

For someone who does not follow the web's history, how would one produce direct evidence that the bias exists